Fuse

ABSTRACT

1. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc rotatable in said recess about said longitudinal axis, there being oppositely disposed grooves in the abutting faces of said body portion and said disc, the groove in said disc extending first arcuately then radially outwardly, the groove in said body extending radially outwardly, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position.

United States Patent Shelley et a1. Get. 7, 1975 FUSE 1,975,809 10/1934 Teitscheid 102/78 [75] Inventors: Edwin S e y, Ne Roc e e; 2,495,432 1/1950 Thompson 102/79 Harold G. Wenig, Brooklyn, both of N.Y.; Selim S. Podnos, Washington, DC; Alexander Shayne, New York, NY.

The United States of America as represented by the Secretary of the Army, Washington, DC.

Filed: Feb. 23, 1954 Appl. No.: 412,136

Assignee:

References Cited UNITED STATES PATENTS 4/1928 Varaud 102/80 Primary Examiner-Stephen C. Bentley Assistant ExaminerHarold Tudor Attorney, Agent, or Firm-Nathan Edelberg; Robert P. Gibson EXEMPLARY CLAIM 1. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc rotatable in said recess about said longitudinal axis, there being oppositely disposed grooves in the abutting faces of said body portion and said disc, the groove in said disc extending first arcuately then radially outwardly, the groove in said body extending radially outwardly, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position.

16 Claims, 6 Drawing Figures US Patent 00. 7,1975 Sheet 1 of 2 3,910,193

Figi 4i- 4 45- lNl/sNToes 3 Edwin EElh alley Huruld llwenig Selim 5- Foch-L135 5 Alexander Shayne 4W W M ATTURNEYS FUSE The present invention relates to a fuse.

More particularly the present invention relates to a mechanically functioning, point detonating fuse for antiaircraft rotating projectiles which incorporates a selfdestruction feature.

A paramount and necessarily important requirement of all fused projectiles is that the fuse be inoperative or bore safe while the projectile is traversing the bore of the weapon. Antiaircraft projectiles in addition are more effective when they are made responsive to impact with a desired target, and when means to assure a slight delay in detonation of the projectile after impact is incorporated into the fuse, to achieve more effective destruction of the intended target. A delay in time of 3001000 micro seconds, which corresponds approximately to additional travel of 6 inches to 24 inches of the projectile within the target after impact has been found by experiment to be a requisite for optimum destruction.

Another necessary requirement of antiaircraft projectiles, which arises because of the elusive nature of the target to be destroyed, is the need for the fuse to accomplish its function to detonate the projectile when the projectiles nose fails to directly impact the target, and instead only grazes it.

Equally importantly in antiaircraft firing is the provision of means to provide self-destruction of the fuse in the event the projectile misses the target entirely, since in modern warfare antiaircraft firing more often than not may occur over friendly territory where much danger to life and limb may be occasioned by detonation of the projectile upon impact with the ground instead of in the air.

It is accordingly an important aim of this invention to provide a fuse for an antiaircraft projectile in which a mechanically functioning time sequence delay element is substituted for the well known escapement devices; the time delay element being constructed and arranged so as to be released either on direct impact with a target, or when the target is merely grazed, or at a predetermined time interval after the target is completely missed.

It is also contemplated to provide a centrifugally re sponsive ball cam rotor and including a detonator, normally biased to safe position, and comprising an arcuate camming slot to provide a path for a guide ball which moves outwardly under centrifugal force to rotate the rotor to arming position, the ball also cooperating with a recess in the projectile body when the rotor is in fully armed position to maintain the fuse armed when decay in spin occurs.

A further consideration impelling the conception of this invention is a centrifugally responsive governor and inertia ring cooperating with a control rod to set the time sequence delay firing mechanism in motion either to detonate the projectile at any slight impact with a target, or to effect detonation for selfdestruction of the projectile in the event the target is completely missed.

Another attainment sought is the construction of a fuse for an antiaircraft projectile having the essentials above indicated, and involving a minimum number of moving parts adaptable for mass production to achieve proper functional relation of parts with maximum certainty of fuse operation.

It is also a specific desire to provide a fuse which reduces malfunctioning to a minimum regardless of whether the target is a heavy or light target and irrespective of whether the impact of the projectile is normal to or at an angle to the target to be destroyed.

Additional objects, advantages and features of the invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention as will appear from the following description and accompanying drawings, wherein:

FIG. 1 is a longitudinal section of the fuse of this invention.

FIG. 2 is a section taken on line 2-2 of FIG. 1.

FIG. 3 is a transverse section taken on line 33 of FIG. 2 and illustrating the rotor actuating ball received in the camming slot.

FIG. 4 is a transverse section taken on line 4-4 of FIG. 2.

FIG. 5 is a transverse section taken on line 5-5 of FIG. 2, and

FIG. 6 is a transverse section taken on line 66 of FIG. 2.

Referring to the drawings, reference character 1 designates the fuse generally which comprises a forwardly tapering body portion 2, having a forward axial bore 3 extending rearwardly for a depth which is approximately one third the length of portion 2, and which in turn is in axial alinement with a second shallow depth bore 4 of slightly reduced diameter disposed rearwardly thereof and forming therebetween a shoulder 5. Bore 4 communicates rearwardly with an enlarged bore 6 having a diameter, slightly larger than the diameter of bore 3, and equal approximately to its depth to form an open ended spring housing, as later to be described. The remainder of forward body portion 2 is again counter bored rearwardly at 7, commencing with a portion 8 of increased diameter immediately rearwardly of and coaxial with counterbore 6, and being stepped rearwardly to increasing diameters as at 9 to the end thereof, there being an internally screw-threaded portion 10 formed at the extreme end of the counterbore 7 as clearly seen in FIGS. 1 and 2.

Reference character 11 designates a forwardly tapering medial body portion having a peripheral surface 12 merging with the external surface of portion 2, and provided forwardly with a threaded tenon 13 to engage threads 10, and a rearwardly extending threaded tenon 14 to mate with threads 15 formed in a recess 16 in the forward face of the projectile 117, of which the fuse 1 forms a part. Body portion 11 is provided with a counterbore 18 having a diameter approximately equal to the diameter of a medial portion of counterbore 7, and extending rearwardly from its forward face 19, almost to its rear end to form a transverse wall 20, to the rear of which is formed an axial recess 21 in projectile 17 to house a booster charge 22 in the well known manner. Projectile 17 is also provided with a chamber 23 rearwardly of booster 22 and in detonating relation therewith to receive an explosive charge 24 of any acceptable composition. The forward body portion 2 is provided with an annular peripheral recess 25 into which is crimped the inwardly turned rear end 26 of a conical impact collapsible sheet metal shield 27, provided with a rounded nose 28 which is spaced axially forwardly of the forward end of body portion 2 to form a space 29.

The effective operation of the fuse is dependent upon the following mechanically functioning elements cooperating as the result of spin and linear acceleration to detonate the fuse either at impact, or when a target is grazed, or when self-destruction is required, namely ball cam rotor 30, time delay sequence release mechanism 32, a centrifugally operable governor mechanism 34, and an inertia operated mechanism 36.

BALL CAM ROTOR The ball cam rotor comprises a cylindrical rotating element or disc loosely received in the lower half of counterbore l8 and arranged within the recess with its rear face 41 abutting the forward face of transverse wall 20. The disc 40 is arranged to rotate about a stud shaft 42 having one end received in a central recess 43 in transverse wall 20 and the other end received in a central recess 44 formed in a cylindrical plug or block 45, later to be described and press fitted into the unoccupied half of counterbore 18. To facilitate rotation of disc 40, an inner ball bearing race 46 is made integral about shaft 42. The outer race 47 is formed integrally with rotor disc 40, and the well known ball bearings 48 are received therebetween. A cylindrical recess 49 is formed in the forward face of disc rotor 40 coaxial about shaft 42, and received in one side of recess 49 is an eccentrieally disposed axially extending detonator holder 50 integral with block 45, and into which is press fitted a detonator capsule 51. A torsion spring 52 concentric about shaft 42 and having one end secured to block 45 and the other end fastened to rotor disc 40, normally urges the disc into unarmed position such that an eccentric longitudinal flash passage 53 through the bottom wall of disc 40 is out of alinement with detonator 51. If desired a relatively insensitive explosive lead may be placed in flash passage 53. When the rotor is moved to armed position, detonator 51 and flash passage 53 are alined with a detonator lead 54 extending through transverse wall 20 and in detonating relation with booster 22 to provide an explosive train for the booster when detonator 51 is struck by a firing pin. To provide rotation for rotor disc 40 (See FIG. 3) the rearward face of the disc is provided with a slot 55 which extends first arcuately and then radially to correspond with a radial slot 56 in transverse wall 20 which is integral with medial body portion 11. Portion 11 may be termed a stator. A ball 57 is received between the stator and rotor and is of such dimensions that it engages both the stator slot 56 and rotor slot 55. When the main projectile body and hence the stator is rotating about an axis approximately coincident with the axis of rotor shaft 42, centrifugal force acts to force ball 57 outwardly along the slot 56 in the stator. Under these conditions the ball can move only by forcing rotor 40 to rotate with respect to the stator. Any desired time to effect full arming for a predetermined angular distance of the rotor may be set depending on the mass of the ball 57 and rotor 40, and the speed of rotation of the projectile. When the rotor is in fully armed position, ball 57 is disposed so that it is partly within slots 56 and 55 and partly within a radially alined slot 58 in stator 11, so that the ball acts as a detent, assisted by spring 52, to lock the rotor in armed position. It is within the purview of the device to effect rotation through any desired angle, either less than or more than 360 by suitably cutting the cam slot in the face of the rotor. Also, more than one ball may be used to provide more balanced driving torque, without departing from the scope of the invention.

TIME DELAY SEQUENCE RELEASE MECHANISM The time delay sequence mechanism 32 is intended to provide a short delay, mechanically, of the order of 0.001 second after the fuse impacts the target and before detonation begins, or when rotational velocity has decreased to a predetermined value. The mechanism is received for the most part in the forward end of counterbore l8 and comprises the before mentioned cylindrical block or plug 45 snugly received in counterbore 18 so as to be integral with medial body portion 11. Block 45 is provided with a relatively wide diametral slot 60 (See FIG. 2) in which is received a firing bar 61 mounted for pivotal rotation upon a pivot pin 62 normal to the longitudinal axis of the projectile, such that as the bar rotates, a firing pin 63 protruding from the rear face of bar 61 is placed in forcible contact with detonator 51 to initiate the same. The bar is normally arranged so that its rear end angularly abuts the forward end of shaft 42, and its forward end engages the inner face of one leg of a slotted slide member 64 which is adapted to slide in a cutaway portion or guide way 65 in the forward face of block 45. As seen in FIG. 1, slide member 64 is released to slide downwardly when a later to be described control plunger is forced rearwardly thereby releasing firing bar 61 for rotation in' a clockwise direction by virtue of a torsion spring 61 so that firing pin 63 forcibly contacts and initiates detonator 51. A stop member 66 forwardly of and parallel to pivot pin 62 and disposed immediately to the right of bar 61 prevents counter clockwise rotation of the firing bar, and limits the rearward movement of the later to be described control plunger. A compression spring 67 FIG. 4) received in cutaway portion 65 abuts the left side of slide 64 to bias it for movement toward the right when released. Alternatively, motivating power for moving the slide member 64 to the right may be supplied by centrifugal force.

CENTRIFUGALLY OPERABLE GOVERNOR Governor 34 comprises means centrifugally responsive to actuate control plunger 70 to release slide member 64. The mechanism is locked until a predetermined rotational speed is reached, at which time other elements are released to function when the rotational speed decreases to a predetermined value. The ele ments forming the governor and impact responsive control plunger comprise an impact sleeve 71 secured to the inner face of nose 28 and extending rearwardly axially for a short distance into space 29. A cylindrical sleeve 72 having an axial bore 73 occupies almost the entire length of axial bore 3 and is snugly received therein to tightly abut the forward face of a ball stop washer 74 which occupies the remainder of axial bore 3 and in turn abuts shoulder 5. Control plunger 70 is an axially slidable rod comprising a first forward cylindrical portion 75 extending forwardly through washer 74 to slidably engage the rearmost wall portion of axial bore 73. Cylindrical portion 75 then extends rearwardly to the rear edge of bore 6 at which point a first cylindrical enlargement 76 is formed integrally therewith to correspond to a second enlargement 77 spaced rearwardly axially a short distance therefrom and between which plunger 70 is secn as a section 78 of diameter smaller than cylindrical portion 75. The plunger is again reduced in diameter at 79, enlarged again at 80, reduced again at 81 and enlarged again at its rearward end 82, which last enlargement lies within the slot of slide 64 to normally maintain it in firing bar locking position. Concentric about the rearmost end of control plunger 70 is a cylindrical plug 83 stepped as at 84 to tightly engage the stepped wall rearwardly in counterbore 9, and arranged so that its rear face abuts the forward face of block 45. Plug 83 is provided with an axial bore 84 to be slidingly engaged by enlargement 80 and formed therein are three equi-angularly spaced radial slots or recesses 85 in its forward face converging about reduced portion 79 to receive a portion of the now to be described flyweights 86 forming a part of the centrifugal governor. (See FIG. 5). The flyweights 86 are seen as right angled bell crank members in cross section illustrated in FIG. 2, and comprise three separate tubular sections 87 equilaterally concentric about reduced portion 79, and each pivotable radially within a corresponding radial recess 85 upon equilaterally arranged pivot pins 88 spanning recesses 85 and secured to plug 83. To the outer peripheral surface of each section 87 are fastened arms 89 extending radially inwardly and provided on their inner ends with enlarged buttons 90 which are received between enlargements 77 and 80 to face upon reduced portion 79 of the control plunger. (See FIG. 5). At right angles to arms 89, three forwardly extending arms 90 are secured to tubular sections 87, and each arm 90 ends in a tubular section 91 equilaterally concentric about reduced portion 78. By this arrangement, it can readily be seen that flyweights 86 may reciprocate control plunger 70 axially forwardly or rearwardly depending upon the inner or outer movement of the flyweights and in response to centrifugal force. Received in spring housing 6 and concentric about cylindrical portion 75 of the control plunger there is arranged a compression spring 92 having one end engaging the forward end of housing 6 and the rear end contacting a disc-like spring abutment 93 concentric about portion 75 and secured integrally to enlargement 76. The spring 92 serves to normally bias control plunger 70 rearwardly. Means are also provided to normally prevent rearward motion of the control plunger. This means comprises a ball 94 resting in a hole 95 formed partially in ball washer 74 and partially in sleeve 72, and adapted to engage a spherical recess 96 formed in the forward end of the control plunger. The wall forming the hole portion in washer 74 is beveled inwardly to form a camming face 97 against which the ball rests when the control rod 70 is in rearward position, and when the rod is moved forward slightly, centrifugal force will urge the ball into a transverse slot 98 extending between hole 95 and the outer peripheral surface of the fuse. A firing plunger 99 is also slidable within bore 73 and is seen as a tubular member having a forward pointed end 100 received within impact sleeve 71 and its rearward end 101 spaced a short distance axially forwardly of the forward end of control rod 70. Upon impact element 28 collapses and impact sleeve 71 drives the firing plunger rearwardly so that it engages and forces the control plunger 70 rearwardly also.

The action of the governor mechanism is as follows. At rest control plunger 70 is locked in place due to the action of spring 92 which forces control rod 70 rearwardly but which is prevented from moving rearwardly by the action of ball 94 resting in spherical recess 96.

As the rotational speed of the projectile increases, the flyweights tend to overcome the force of the spring 92 until, at some predetermined rotational speed, control rod is moved forwardly sufficiently to allow the ball 94 to escape by way of hole and into transverse slot 98, under the influence of centrifugal force. Further increase in rotational speed urges the control rod forwardly but not to an extent to release slide 64. The extent of the forward travel of control rod 70 may be limited by the compressive stress in spring 92, or by a stop (not shown) built into the fuse housing. The control rod may now be driven rearwardly to release slide 64 upon point-impact with its intended target. In the absence of point-impact on the target, control rod 70 will be gradually forced rearward upon decay in spin and due to a decrease in centrifugal force since the flyweights will exert less forward thrust on the control rod. At a predetermined rotational speed the governor spring will overcome the force of the flyweights to an extent to force control rod 70 rearwardly to an extent to free slide 64, thereby initiating detonation of the round.

INERTIA OPERATED MECHANISM Although decay in spin may provide for selfdestruction of the projectile in the last described manmet, more positive means to assure self-destruction and to facilitate detonation of the round on graze impact has been found desirable. In order to accomplish this purpose an inertia ring 105 is loosely received in counterbore 8, and when in normal position is disposed concentrically about flyweights 86, with its rearward face abutting the forward face of the centrifugal governor support on block 83.

The outer contour of inertia ring 105 engaging the wall of counterbore 9 is rounded or curved as at 106, and its inner contour 107 is tapered in a rearward direction to present a face which is normally spaced radially outwardly of flyweights 86. Inertia ring 105 is a seismic element which responds to the slightest jarring and which will roll forward on. graze impact against one or more of the flyweights 86 to force control rod 70 rearward to release the firing bar to thereby initiate detonation of the round.

If the target is missed entirely inertia ring 105 will creep forwardly as the projectile commences to decelerate. Since the outer contour of the ring is curved the ring will tend to roll rather than to slide forwardly, and the control rod 70 will be gradually forced rearwardly and assisted by a decrease in centrifugal force caused by a decay in spin. At some predetermined rotational speed, spring 92 will overcome the effect of the flyweights to force control rod 70 rearwardly to an extent sufficient to release slide 64, and consequently firing bar 61 to initiate detonation of the round. It is important to note that due to the outer contour of the inertia ring, and its tendency to roll rather than to slide, the coefficient of friction tending to restrain the ring from forward movement will be that co-efficient associated with rolling friction rather than the co-efficient associated with sliding friction. This represents a great decrease in the restraining force, and therefore a correspondingly great improvement in the sensitivity of the device to linear decelerations.

The above description discloses a fuse for a rotating projectile which provides the necessary delay after point impact, and which is also effective to initiate detonation upon graze impact, or upon linear deceleration if the target is completely missed. It is to be understood, however, that the illustrated embodiment is only exemplary, and that other arrangements of the component elements may be made without departing from the spirit and scope of the appended claims.

We claim:

1. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc rotatable in said recess about said longitudinal axis, there being oppositely disposed grooves in the abutting faces of said body portion and said disc, the groove in said disc extending first arcuately then radially outwardly, the groove in said body extending radially outwardly, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position.

2. The projectile on claim 1, and including resilient means in said fuse normally biasing said disc in safe po sition.

3. The projectile in claim 1, there being an axially extending recess disposed eccentrically in the forward face of said disc, and a detonator fixed to said body portion and extending into said last named recess.

4. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being'fa coaxial recess formed in said body portion, a cylindrical disc rotatable in said recess on a shaft coincident with said longitudinal axis, there being oppositely disposed grooves formed in the abutting faces of said body portion and said disc, the groove in disc ex tending first arcuately then radially outwardly and the groove in said disc extending radially outwardly, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position, there being an axially extending recess disposed eccentrically in the forward face of said disc, a detonator secured to said body portion and extending into said eccentric recess, and a torsion spring concentric about said shaft normally biasing said disc in safe position.

5. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc in the rearward half of said recess and rotatable on a shaft coincident with said longitudinal axis, there being oppositely disposed grooves formed in the abutting faces of said body portion and said disc, the groove in said disc extending first arcuately then radially outwardly and the groove in said body portion having a radial direction, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position, there being an axially extending recess disposed eccentrically in the forward face of said disc, a detonator secured to said body portion and extending into said eccentric recess, a first torsion spring concentric about said shaft normally biasing said disc in safe position, means received in said coaxial recess including a pivot pin normal to the longitudinal axis of said projectile, a firing bar rotatably mounted on said pivot pin, a firing pin carried by the rear face of said firing bar and a second torsion spring disposed about said pivot pin adapted to rotate said firing bar and said firing pin when said disc is in armed position to initiate said detonator.

6. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, an arming disc rotatable in the rearward half of said coaxial recess there being a bore formed in said disc, a detonator secured to said body portion and eccentrically disposed in the forward face thereof, means engaging said disc and said body portion and movable in response to centrifugal force to rotate said disc to armed position, sequence delay mechanism for initiating said detonator comprising, a slide transversely slidable in a guideway formed forwardly in said coaxial recess, a firing bar rotatable on a transverse axis in said recess intermediate said disc and said slide, said firing bar lying crosswise of said longitudinal axis with its forward end received in a slot in said slide when said fuse is unarmed, resilient means normally biasing said firing bar for movement of the forward end thereof away from said slide when the firing bar is released, a firing pin mounted on the forward end of said firing bar adapted to initiate said detonator when said fuse is armed, and releasable means normally engaging and maintaining said slide in position to retain said firing bar and firing pin out of engagement with said detonator.

7. The projectile in claim 6, and including resilient means biasing said slide to firing bar release position.

8. The projectile in claim 6, and including means responsive to point-impact of said fuse engaging said releasable means to move the same to slide releasing position.

9. The projectile in claim 6, and including means responsive to graze-impact of said fuse engaging and moving said releasable means to slide releasing position.

10. The projectile in claim 6, and including means responsive to deceleration of said projectile to move said releasable means to slide releasing position.

1 1. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a detonator eccentrically disposed rearwardly in said coaxial recess, and sequence delay mechanism for initiating said detonator, said mechanism comprising a slide transversely slidable in a guideway formed forwardly in said coaxial recess, a firing bar rotatable on a transverse axis in said recess intermediate said detonator and said slide, a firing pin integral with the forward end of said firing bar and adapted to forcibly engage said detonator, resilient means normally biasing said firing bar and firing pin into detonator engaging position, said firing bar having its forward end received in a slot formed in said slide and lying crosswise of said longitudinal axis when said fuse is unarmed, resilient means normally biasing said slide to position to release said firing bar, and releasable means normally locking said slide in position to maintain said firing bar and firing pin out of engagement with said detonator, said last named means being responsive to impact of said fuse to sequentially release said slide and said firing bar.

12. In a rotating projectile, a fuse comprising a main body portion, a rotor in said body portion rotatable from safe position to armed position and including an explosive lead, a detonator in said fuse, means in said body movable from first locked position to second position to initiate said detonator when said rotor has moved to said armed position, transversely slidable means in said body portion normally retaining said detonator initiating means in first locked position, resilient means biasing said slidable means to position unlocking said detonator initiating means, means axially reciprocable in said body portion normally maintaining said slidable means in position to lock said detonator initiating means, detent means in said fuse normally restraining said axially reciprocable means against movement, said detent means being responsive to predetermined centrifugal force to release said axially reciprocable means, and means in said fuse responsive to point impact of said fuse to drive said axially reciprocable means rearwardly to release said slidable means, whereby said detonator is initiated.

13. A fuse for a rotating projectile having a main body portion and comprising, a detonator in said body portion, a sequence delay mechanism including a firing pin resiliently biased to contact and to initiate said detonator, a slotted slide member adapted to engage said pin and means for normally locking said firing pin in out-of-engagement position with said detonator and comprising, a control rod axially reciprocable in said body portion, one end of said control rod engaging said slide member to release said firing pin, resilient means biasing said control rod to firing pin release position, a detent cooperating with said resilient means to normally lock said control rod in position to engage said firing pin and including a ball having a portion received in a spherical cavity in said control rod and a portion received in a radially alined hole formed in said body portion, there being a transverse bore formed in said body portion in radial alinement with said hole to permit outward movement of said ball in response to centrifugal force, a plurality of right angled flyweights pivotally mounted in a recess coaxial about said control rod, each of said flyweights having the inner end of one leg received in an annular recess formed in the peripheral surface of said control, and the other leg adapted to swing outwardly in response to centrifugal force to move said control rod forwardly against the bias of said resilient means at a predetermined rotational speed to force said detent ball into said transverse bore, a firing plunger forwardly of and in axial alinement with said control rod adapted to be forced rearwardly at pointimpact of said fuse to contact and move said control rod out of engagement with said slide member.

14. The fuse in claim 13 and including an inertia ring concentric about said flyweights and having an inner face adapted to engage and to move said flyweights inwardly upon graze impact to move said control rod out of engagement with said slide member.

15. The fuse in claim 14 wherein the inner face of said inertia ring creeps forwardly upon decay in linear acceleration to engage said flyweights whereby said control rod is moved out of engagement with said slide member.

16. In a rotating projectile, a fuze, a detonator in said fuze, a rotor for housing said detonator, an explosive lead eccentrically disposed in said rotor, means responsive to centrifugal force to move said rotor from first safe position to second armed position to aline said lead with said detonator, resilient means normally biasing said rotor in safe position, a percussive element in said fuse movable to position to initiate said detonator, said percussive element comprising a firing bar pivotable upon a transverse axis in said fuze, a firing pin secured to one end of said firing bar, a spring normally biasing said firing bar and pin to detonator engaging position, said detonator initiating said explosive lead when said rotor is in armed position, means transversely slidable in said fuze normally retaining said percussive element out of engagement with said detonator, resilient means in said fuze normally biasing said slidable means to position to release said percussive element, an axially reciprocal control rod in said fuze normally maintaining said slidable means in percussive element locking position, detent means in said fuze normally locking said control rod in position to lock said slidable means against movement, said detent means being responsive to predetermined centrifugal force to release said control rod, and means in said fuze responsive to point impact of said fuze to move said control rod to position to release said slidable means, whereby said detonator is initiated. 

1. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc rotatable in said recess about said longitudinal axis, there being oppositely disposed grooves in the abutting faces of said body portion and said disc, the groove in said disc extending first arcuately then radially outwardly, the groove in said body extending radially outwardly, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position.
 2. The projectile on claim 1, and including resilient means in said fuse normally biasing said disc in safe position.
 3. The projectile in claim 1, there being an axially extending recess disposed eccentrically in the forward face of said disc, and a detonator fixed to said body portion and extending into said last named recess.
 4. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc rotatable in said recess on a shaft coincident with said longitudinal axis, there being oppositely disposed grooves formed in the abutting faces of said body portion and said disc, the groove in disc extending first arcuately then radially outwardly and the groove in said disc extending radially outwardly, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position, there being an axially extending recess disposed eccentrically in the forward face of said disc, a detonator secured to said body portion and extending into said eccentric recess, and a torsion spring concentric about said shaft normally biasing saiD disc in safe position.
 5. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a cylindrical disc in the rearward half of said recess and rotatable on a shaft coincident with said longitudinal axis, there being oppositely disposed grooves formed in the abutting faces of said body portion and said disc, the groove in said disc extending first arcuately then radially outwardly and the groove in said body portion having a radial direction, a ball received in said grooves and responsive to centrifugal force to rotate said disc from safe position to armed position, there being an axially extending recess disposed eccentrically in the forward face of said disc, a detonator secured to said body portion and extending into said eccentric recess, a first torsion spring concentric about said shaft normally biasing said disc in safe position, means received in said coaxial recess including a pivot pin normal to the longitudinal axis of said projectile, a firing bar rotatably mounted on said pivot pin, a firing pin carried by the rear face of said firing bar and a second torsion spring disposed about said pivot pin adapted to rotate said firing bar and said firing pin when said disc is in armed position to initiate said detonator.
 6. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, an arming disc rotatable in the rearward half of said coaxial recess there being a bore formed in said disc, a detonator secured to said body portion and eccentrically disposed in the forward face thereof, means engaging said disc and said body portion and movable in response to centrifugal force to rotate said disc to armed position, sequence delay mechanism for initiating said detonator comprising, a slide transversely slidable in a guideway formed forwardly in said coaxial recess, a firing bar rotatable on a transverse axis in said recess intermediate said disc and said slide, said firing bar lying crosswise of said longitudinal axis with its forward end received in a slot in said slide when said fuse is unarmed, resilient means normally biasing said firing bar for movement of the forward end thereof away from said slide when the firing bar is released, a firing pin mounted on the forward end of said firing bar adapted to initiate said detonator when said fuse is armed, and releasable means normally engaging and maintaining said slide in position to retain said firing bar and firing pin out of engagement with said detonator.
 7. The projectile in claim 6, and including resilient means biasing said slide to firing bar release position.
 8. The projectile in claim 6, and including means responsive to point-impact of said fuse engaging said releasable means to move the same to slide releasing position.
 9. The projectile in claim 6, and including means responsive to graze-impact of said fuse engaging and moving said releasable means to slide releasing position.
 10. The projectile in claim 6, and including means responsive to deceleration of said projectile to move said releasable means to slide releasing position.
 11. In a rotating projectile symmetrical about a longitudinal axis, a fuse having a main body portion, there being a coaxial recess formed in said body portion, a detonator eccentrically disposed rearwardly in said coaxial recess, and sequence delay mechanism for initiating said detonator, said mechanism comprising a slide transversely slidable in a guideway formed forwardly in said coaxial recess, a firing bar rotatable on a transverse axis in said recess intermediate said detonator and said slide, a firing pin integral with the forward end of said firing bar and adapted to forcibly engage said detonator, resilient means normally biasing said firing bar and firing pin into detonator engaging position, said firing bar having its forward end received in a slot formed in said slide and lying crosswise of said longitudinal axis when said fuse is unarmed, resilient means normally biasing said slide to position to release said firing bar, and releasable means normally locking said slide in position to maintain said firing bar and firing pin out of engagement with said detonator, said last named means being responsive to impact of said fuse to sequentially release said slide and said firing bar.
 12. In a rotating projectile, a fuse comprising a main body portion, a rotor in said body portion rotatable from safe position to armed position and including an explosive lead, a detonator in said fuse, means in said body movable from first locked position to second position to initiate said detonator when said rotor has moved to said armed position, transversely slidable means in said body portion normally retaining said detonator initiating means in first locked position, resilient means biasing said slidable means to position unlocking said detonator initiating means, means axially reciprocable in said body portion normally maintaining said slidable means in position to lock said detonator initiating means, detent means in said fuse normally restraining said axially reciprocable means against movement, said detent means being responsive to predetermined centrifugal force to release said axially reciprocable means, and means in said fuse responsive to point impact of said fuse to drive said axially reciprocable means rearwardly to release said slidable means, whereby said detonator is initiated.
 13. A fuse for a rotating projectile having a main body portion and comprising, a detonator in said body portion, a sequence delay mechanism including a firing pin resiliently biased to contact and to initiate said detonator, a slotted slide member adapted to engage said pin and means for normally locking said firing pin in out-of-engagement position with said detonator and comprising, a control rod axially reciprocable in said body portion, one end of said control rod engaging said slide member to release said firing pin, resilient means biasing said control rod to firing pin release position, a detent cooperating with said resilient means to normally lock said control rod in position to engage said firing pin and including a ball having a portion received in a spherical cavity in said control rod and a portion received in a radially alined hole formed in said body portion, there being a transverse bore formed in said body portion in radial alinement with said hole to permit outward movement of said ball in response to centrifugal force, a plurality of right angled flyweights pivotally mounted in a recess coaxial about said control rod, each of said flyweights having the inner end of one leg received in an annular recess formed in the peripheral surface of said control, and the other leg adapted to swing outwardly in response to centrifugal force to move said control rod forwardly against the bias of said resilient means at a predetermined rotational speed to force said detent ball into said transverse bore, a firing plunger forwardly of and in axial alinement with said control rod adapted to be forced rearwardly at point-impact of said fuse to contact and move said control rod out of engagement with said slide member.
 14. The fuse in claim 13 and including an inertia ring concentric about said flyweights and having an inner face adapted to engage and to move said flyweights inwardly upon graze impact to move said control rod out of engagement with said slide member.
 15. The fuse in claim 14 wherein the inner face of said inertia ring creeps forwardly upon decay in linear acceleration to engage said flyweights whereby said control rod is moved out of engagement with said slide member.
 16. In a rotating projectile, a fuze, a detonator in said fuze, a rotor for housing said detonator, an explosive lead eccentrically disposed in said rotor, means responsive to centrifugal force to move said rotor from first sAfe position to second armed position to aline said lead with said detonator, resilient means normally biasing said rotor in safe position, a percussive element in said fuse movable to position to initiate said detonator, said percussive element comprising a firing bar pivotable upon a transverse axis in said fuze, a firing pin secured to one end of said firing bar, a spring normally biasing said firing bar and pin to detonator engaging position, said detonator initiating said explosive lead when said rotor is in armed position, means transversely slidable in said fuze normally retaining said percussive element out of engagement with said detonator, resilient means in said fuze normally biasing said slidable means to position to release said percussive element, an axially reciprocal control rod in said fuze normally maintaining said slidable means in percussive element locking position, detent means in said fuze normally locking said control rod in position to lock said slidable means against movement, said detent means being responsive to predetermined centrifugal force to release said control rod, and means in said fuze responsive to point impact of said fuze to move said control rod to position to release said slidable means, whereby said detonator is initiated. 